Upflow Installations; Counterflow Installations; Gas Piping Checks - Amana MES80 Manual

• Install a drip leg to trap dirt and moisture before it can
enter the gas valve. The drip leg must be a minimum
of three inches long.
• Install a 1/8" NPT pipe plug fitting, accessible for test
gage connection, immediately upstream of the gas
supply connection to the furnace.
• Use two pipe wrenches when making connection to
the gas valve to keep it from turning. The orientation
of the gas valve on the manifold must be maintained
as shipped from the factory.
• Install a manual shutoff valve between the gas
meter and unit within six feet of the unit. If a union
is installed, the union must be downstream of the
manual shutoff valve, between the shutoff valve and
the furnace.
• Tighten all joints securely.
• Connect the furnace to the building piping by one of
the following methods:
–
Rigid metallic pipe and fittings.
–
Semi-rigid metallic tubing and metallic fittings.
Aluminum alloy tubing must not be used in exterior
locations.
–
Use listed gas appliance connectors in accordance
with their instructions. Connectors must be fully in
the same room as the furnace.
–
Protect connectors and semi-rigid tubing against
physical and thermal damage when installed.
Ensure aluminum-alloy tubing and connectors are
coated to protect against external corrosion when
in contact with masonry, plaster, or insulation, or
subjected to repeated wetting by liquids such as
water (except rain water), detergents, or sewage.
Location of Manual Valve
(Installed Ahead of
Ground Joint Pipe Union)
Height Required
By Local Code
Ground Joint Pipe Union
To Be Installed
Ahead of Gas Valve
Drip Leg
OPTIONAL:
Reducing Coupling
1/2" x 1/8" with 1/8"
Pipe Plug to Measure
Line Gas Pressure
General Furnace Layout

Upflow Installations

A ground joint union, drip leg, and manual shutoff valve must
also be supplied by the installer. In some cases, the installer
may also need to supply a transition piece from 1/2" to another
pipe size.
When the gas piping enters through the side of the furnace,
the installer must supply the following fittings starting from
the gas valve:
• Nipple
• Elbow
• Straight pipe to reach the exterior of the furnace.
• A ground joint union, drip leg, and manual shutoff
valve
must also be supplied by the installer.

Counterflow Installations

When the gas piping enters through the side of the furnace,
the installer must supply , the following fittings starting from
the gas valve:
• Nipple
• Elbow
• Straight pipe to reach the exterior of the furnace.
A ground joint union, drip leg and manual shutoff valve must
also be supplied by the installer.

Gas Piping Checks

Before placing unit in operation, leak test the unit and gas
connections.
T
O AVOID THE POSSIBILITY OF EXPLOSION OR FIRE
OR OPEN FLAME TO TEST FOR LEAKS
Check for leaks using an approved chloride-free soap and
water solution, an electronic combustible gas detector, or
other approved testing methods.
NOTE: Never exceed specified pressures for testing. Higher
pressure may damage the gas valve and cause subsequent
overfiring, resulting in heat exchanger failure.
Disconnect this unit and shutoff valve from the gas supply
piping system before pressure testing the supply piping system
with pressures in excess of 1/2 psig (3.48 kPa).
This unit must be isolated from the gas supply system by
closing its manual shutoff valve before pressure testing of
gas supply piping system with test pressures equal to or less
than 1/2 psig (3.48 kPa).
16
WARNING
,
NEVER USE A MATCH
.